1. Field of the Invention
The invention relates to a circuit for generating a trigger pulse delayed within a period of a motion of variable periodic time, the phase lag relative to a zero phase being dependent on the periodic time and other parameters, a zero pulse and angle pulses starting at zero phase being generated, the pulse frequency being inversely proportional to the periodic time, the angle pulses being fed into a counter and correcting data being generated within every period during a constant-time window.
2. Description of the Prior Art
The patent application DE-PS 19 17 389 and the additional patent application DE-PS 20 10 999 show a circuit which requires a reference sequence, a separate trigger sequence, and auxiliary pulses during one period. Essentially, the reference sequence is counted during a constant-time window and gives a correction depending on the speed. Finally, the trigger sequence determines the phase relation between the trigger pulse and a reference phase. Further correction pulses are proposed for a correction depending on the load conditions. It is a disadvantage of this method that the reference sequence and the trigger sequence must be selected by separate auxiliary pulses. There is also a time difference between the reference sequence and the trigger sequence.
DE-AS 19 09 525 shows a circuit in which so-called set-pulses are fed into a counter during a period. Hereafter the trigger pulse is generated by means of counting pulses. It is a disadvantage of this method that the set pulses are generated by a pulse source independent of the motion; this may lead to faults hardly to be cleared.